as soon as possible | asap

Meaning: If you do something as soon as possible (sometimes abbreviated to "asap"), you do it at the first possible opportunity.

For example:

She said she'll be here as soon as possible, so there's no point calling her again. She's coming as quickly as she can.

I'm in a meeting now, but I'll call you back asap.

Note: This phrase is sometimes abbreviated to "asap". It can be written as such, or in conversation it can be pronounced as a two-syllable word "a-sap", or the letters can be pronounced separately as "a-s-a-p".